Height adjusting device for a platform of a treadmill

ABSTRACT

A height adjusting device includes two lifting arms pivotally mounted to a main frame of a treadmill. Each lifting arm has a first end pivotally mounted to the main frame and a second end upwardly extending therefrom. The second end of each of the two lifting arms is pivotally connected to two opposite sides of the platform. A lateral rod has two opposite ends respectively secured on the two lifting arms such that the two lifting arms are synchronously operated and a pivot seat formed on a middle section of the lateral rod. A telescopic rod has a first end pivotally connected to the pivot seat and a second end pivotally mounted to a bottom of the platform for reciprocally driving the lateral rod and the two lifting arms to adjust a height of the platform.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a height adjusting device, and more particularly to a height adjusting device for a platform of a treadmill to adjusting an angle of the platform of the treadmill relative to a supporting surface.

2. Description of Related Art

A conventional height adjusting device in accordance with the prior art shown in FIGS. 6 and 7 comprises two L-shaped linkages (4). Each L-shaped linkage (4) has a first end (41) pivotally connected to a corresponding one side of a platform (5) of the treadmill, a corner (42) pivotally connected to a supporting rod (51) of the platform (5) and a second end pivotally connected to a connector (431) that is pivotally mounted to a adjusting device (6). The adjusting device (6) forward extends relative to the platform (5) and is secured on a seat (511) that is formed on a free end of the supporting rid (51). The free end of the supporting rod (51) abuts against a supporting surface for supporting a front portion of the platform (5) of the treadmill.

The adjusting device (6) includes a sleeve (62) secured on the seat (511) of the supporting rod (51) and having a threaded inner periphery. A threaded rod (61) has a first end screwed into the sleeve (62) and a second end pivotally connected to the connector (431) such that the threaded rod (61) pulls/pushes the connector (431) with the L-shaped linkage (4) to make the L-shaped linkage (4) circularly moved relative to the first end of the L-shaped linkage (4) for adjusting the height of the platform (5) of the treadmill.

The front portion of the platform (5) is pivotally mounted to the supporting rod (51) by the two L-shaped linkages (4) and the height of the front portion of the platform (5) is adjusted by the threaded rod (61) such that the two L-shaped linkages (4) and the threaded rod (61) load most of the gravity from the treadmill during operating. Consequently, a bending stress occurred to the threaded rod (61) and the bending stress corresponds to the extending length of the threaded rod (61). The threaded may be broken and out of order after loading the bending stress for a long time.

Furthermore, the second end (42) of each of the two L-shaped linkages (4) is used as a fulcrum when adjusting the height of the front portion of the platform (5) such that a moment (L1) between the first end (41) and the second end (42) of each of the two L-shaped linkages (4) is necessary and the moment (L1) corresponds to the adjust range of the front portion of the platform (5). When upward folding the platform (5), the moment (L1) may increase the load of the corner (42) of each of the linkages (4) and cannot stably stand the upward folded platform (5).

In addition, the L-shaped linkage (4) downward extends such that a height (H1) is necessary to the front portion of the platform (5) for containing the L-shaped linkages (4) and the adjusting device (6). However, a high center of gravity of treadmill will make the exerciser feel unsafe.

With reference to FIGS. 8 and 9, another conventional height adjusting device is provided to adjust the height of a platform of a treadmill. The conventional height adjusting device includes a gear (71) pivotally mounted to a bottom of the platform (7) and a linkage set (8) pivotally mounted to a main frame (72) of the treadmill. The linkage set (8) includes two L-shaped linkages (81) respectively pivotally mounted to two opposite sides of the main frame (72). Each L-shaped linkage (81) has a first end (811) pivotally connected to a corresponding one of the two opposite sides of the platform (7) and a second end (812) having a connector (82) pivotally connected to the L-shaped linkage (81). A rack (9) has a first end pivotally connected to the connector (82) and a second end extending toward the bottom of the platform (7). The rack (9) and the gear (71) are engaged to each other. The length of the rack (9) is limited because the rack (9) extends toward the bottom of the platform (7). Consequently, the adjust range of the front portion of the platform (7) is limited and the minimum height (H2) cannot be overcome.

The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional height adjusting devices for a platform of a treadmill.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide an improved height adjusting device for a platform of a treadmill. The height adjusting device of the present invention can reduce an original height of a front portion of the platform.

To achieve the objective, the height adjusting device in accordance with the present invention comprises two lifting arms pivotally mounted to a main frame of a treadmill. Each lifting arm has a first end pivotally mounted to the main frame and a second end upwardly extending therefrom. The second end of each of the two lifting arms is pivotally connected to two opposite sides of the platform. A lateral rod has two opposite ends respectively secured on the two lifting arms such that the two lifting arms are synchronously operated and a pivot seat formed on a middle section of the lateral rod. A telescopic rod has a first end pivotally connected to the pivot seat and a second end pivotally mounted to a bottom of the platform for reciprocally driving the lateral rod and the two lifting arms to adjust a height of the platform.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic view of a height adjusting device for a platform of a treadmill in accordance with the present invention;

FIG. 2 is a partially exploded view of a treadmill in which the height adjusting device of the present invention is mounted;

FIG. 3 is an operational side plan view of the height adjusting device when the platform of the treadmill is downward moved to a minimum height;

FIG. 4 is an operational side plan view of the height adjusting device when the platform of the treadmill is upwardly moved to a maximum height;

FIG. 5 is an operational side plan view of the height adjusting device when the platform of the treadmill is upwardly circularly folded;

FIG. 6 is a side plan view of a first conventional height adjusting device for a platform of a treadmill;

FIG. 7 is an operational side plan view of the height adjusting device in FIG. 6, wherein the platform is upwardly circularly folded;

FIG. 8 is an operational side plan view of a second conventional height adjusting device for a platform of a treadmill when the platform is downward moved to a minimum height; and

FIG. 9 is an operational side plan view of the height adjusting device in FIG. 8, wherein the platform is upwardly moved to a maximum height.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and initially to FIGS. 1-3, a height adjusting device (3) for a platform of a treadmill in accordance with the present invention comprises two lifting arms (31) respectively adapted to be pivotally mounted to two opposite sides of a main frame (1) of the treadmill. Each lifting arm (31) has a first end (311) adapted to be pivotally mounted to the main frame (1) and a second end (312) upwardly extending from each of the lifting arms (31). The second end (312) of each of the lifting arms (31) is pivotally connected to a corresponding one of two opposite sides of the platform (2). A lateral rod (33) has two opposite ends respectively secured on the two lifting arms (31) such that the two lifting arms (31) are synchronously operated. The lateral rod (33) has a pivot seat (331) formed on a middle section thereof. The pivot seat (331) has a connecting portion (332) extending therefrom and corresponding to the second end (312) of each of the lifting arm (31). A telescopic rod (32) has a first end pivotally connected to the connecting portion (332) of the pivot seat (331) and a second end pivotally mounted to a bottom of the platform (2). A power source (321) is mounted adjacent the telescopic rod (32) for reciprocally driving the telescopic rod (32) with the lateral rod (33) and the two lifting arms (31) to adjust the height of the platform (2). In the preferred embodiment of the present invention, the telescopic rod (32) is a threaded rod and the power source (321) is a motor.

With reference to FIGS. 3 and 4, the angle between the lifting arm (31) and the bottom of the platform (2) is changed when the total length of the telescopic rod (32) is changed. The platform (2) is forward moved and lifted when the total length of the telescopic rod (32) becomes short, that is, the first end (311) of each of the two lifting arm (31) is used as a fulcrum and the second end (312) of each of the two lifting arms (31) is upwardly circularly moved to lift the platform (2) relative to the first end (311) of each of the two lifting arms (31). On the contrary, the second end (312) of each of the lifting arms (31) is downward circularly relatively to the first end (311) of each of the lifting arms (31) when the front portion of the platform (2) is downward moved.

With reference to FIG. 5, the first end (311) of each of the lifting arms (31) is used as a fulcrum when the platform (2) is upward circularly moved to reduce of the volume of the treadmill for being easily stored.

The treadmill with the present invention does need to previously defined a space under the platform (2) for containing the rotating lifting arm (31) such the original height (H3) of the front portion of the platform (2) is reduced because the second end (312) of each of the lifting arms (31) extends upwardly and the connecting portion (332) of the pivot seat (331) extend to correspond to the second end (312) of each of the lifting arms (31).

Furthermore, the platform (2) does not limit the length of the lifting arms (31) such that the length of each of the lifting arms (31) can be lengthened to enhance the lifting range of the front portion of the platform (2). The lifting arms (31) is moved with the platform (2) when the platform (2) is upward circularly moved for being folded to reduce the stored volume of the treadmill such that the moment (L2) of folding the platform (2) is shortened and the lifting arms (31) can stably support the platform (2) after being folded.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

1. A height adjusting device for a platform of a treadmill, comprising: two lifting arms respectively adapted to be pivotally mounted to two opposite ends of a main frame of the treadmill, each lifting arm having a first end adapted to be pivotally mounted to the main frame and a second end upwardly extending from each of the two lifting arms, the second end of each of the two lifting arms adapted to be pivotally connected to a corresponding one of two opposite sides of the platform; a lateral rod having two opposite ends respectively secured on the two lifting arms such that the two lifting arms are synchronously operated, the lateral rod having a pivot seat formed on a middle section thereof, the pivot seat having a connecting portion extending therefrom and corresponding to the second end of each of the two lifting arms; and a telescopic rod having a first end pivotally connected to the connecting portion of the pivot seat and a second end adapted to be pivotally mounted to a bottom of the platform for reciprocally driving the lateral rod and the two lifting arms to adjust a height of the platform.
 2. The height adjusting device as claimed in claim 1 further comprising a power source mounted adjacent the telescopic rod for reciprocally driving the telescopic rod.
 3. The height adjusting device as claimed in claim 1, wherein the telescopic rod is a threaded rod.
 4. The height adjusting device as claimed in claim 2, wherein the telescopic rod is a threaded rod. 